Network operators are faced with the challenge of deploying and managing middleboxes (also called inline services) such as firewalls within their broadband access, datacenter or enterprise networks. Due to the lack of available protocols to route traffic through middleboxes, operators still rely on error-prone and complex low-level configurations to coerce traffic through the desired set of middleboxes. Built upon the recent software-defined networking (SDN) architecture and OpenFlow protocol, this paper proposes StEERING, short for SDN inlinE sERvices and forwardlNG. It is a scalable framework for dynamically routing traffic through any sequence of middleboxes. With simple centralized configuration, StEERING can explicitly steer different types of flows through the desired set of middleboxes, scaling at the level of per-subscriber and per-application policies. With its capability to support flexible routing, we further propose an algorithm to select the best locations for placing services, such that the performance is optimized. Overall, StEERING allows network operators to monetize their middlebox deployment in new ways by allowing subscribers flexibly to select available network services.

Over the last decade, programmable Network Processors (NPs) have become widely used in Internet routers and other network components. NPs enable rapid development of complex packet processing functions as well as rapid response to changing requirements. In the network research community, the use of NPs has been limited by the challenges associated with learning to program these devices and with using them for substantial research projects. This paper reports on an extension to the Open Network Laboratory testbed that seeks to reduce these "barriers to entry" by providing a complete and highly configurable NP-based router that users can access remotely and use for network experiments. The base router includes support for IP route lookup and general packet filtering, as well as a flexible queueing sub-system and extensive support for performance monitoring. In addition, it provides a plugin environment that can be used to extend the router's functionality, enabling users to carry out significant network experiments with a relatively modest investment of time and effort. This paper describes our NP router and explains how it can be used. We provide several examples of network experiments that have been implemented using the plugin environment, and provide some baseline performance data to characterize the overall system performance. We also report that these routers have already been used for ten non-trivial projects in an advanced architecture course where most of the students had no prior experience using NPs.